ASoC: ti: davinci-mcasp: Remove unnecessary conditional

Instead of double validating of_node, return value of
the boolean property directly.

We can't remove ifdeffery, because in OF_GPIO=n cases
it might bring unwanted surprises.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20211202205612.76216-2-andriy.shevchenko@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>